Title: Paper by FiftyThree
Summary: Beautifully designed digital sketchbook for any age
Pros: The intuitive design makes this easy for anyone to use.
Cons: Experiencing the app at its fullest (with in-app purchases and Pencil stylus) is likely cost-prohibitive for most classrooms.
Bottom Line: Even at the basic (free) level, the simplicity and effectiveness of the app make this a powerful sketch tool for the iPad.